In radio systems such as M-WiMAX, WLAN, and LTE, radio terminals are requested to have high reception sensitivity to secure wide communication areas. On the other hand, the radio terminals are requested to be reduced in size. There is an increasing demand for a one-chip LSI mixedly mounted with an analog unit and a digital unit of a radio communication system. In the one-chip LSI, it is likely that spurious due to an N-times harmonic of a clock generated by the digital unit leaks into the analog unit and deteriorates a reception characteristic. Therefore, measures for preventing the spurious from getting on the analog unit could be applied.